Kim Jone Un's uncle Jang Song Thaek is dragged into court by uniformed personnel prior to last month's execution.

By Eric Baculinao and Alexander Smith, NBC News

BEIJING -- North Korean leader Kim Jong Un's powerful uncle was stripped naked, thrown into a cage, and eaten alive by a pack of ravenous dogs, according to a newspaper with close ties to China's ruling Communist Party.

The man who was believed to be in charge of training his young nephew to take over was executed as a traitor, indicating a shake-up in Kim Jong Un's regime. NBC's Andrea Mitchell reports.

The official North Korean account on Dec. 12 did not specify how Jang was put to death.

U.S. officials told NBC News on Friday that they could not confirm the reports. "This is not ringing any bells here," said one senior official.

Hong Kong-based pro-Beijing newspaper Wen Wei Po reported that Jang and his five closest aides were set upon by 120 hunting hounds which had been starved for five days.

Kim and his brother Kim Jong Chol supervised the one-hour ordeal along with 300 other officials, according to Wen Wei Po. The newspaper added that Jang and other aides were "completely eaten up."

The newspaper has acted as a mouthpiece for China's Communist Party. The report may be a sign of the struggle between those in the party who want to remain engaged with North Korea and those who would like to distance themselves from Kim's regime.

Jang was seen by many experts as a regent behind North Korea's Kim dynasty and a key connection between the hermit nation and its ally China.

In the highly scripted execution, North Korea accused him of "attempting to overthrow the state by all sorts of intrigues and despicable methods with a wild ambition to grab the supreme power of our party and state."

Kim's government also accused him of of corruption, womanizing, gambling and taking drugs, and referred to him as "despicable human scum."

Alexander Smith reported from London; NBC News' Robert Windrem contributed to this report.

"Despicable human scum...worse than a dog" is how North Korean state media described the once-powerful uncle of leader Kim Jong-un. Jang Song Thaek was executed after admitting trying to "overthrow the state". The dramatic news has provoked fears of instability in the nuclear-armed state. ITV's John Sparks reports.